While the QAS has attempted to contact all copyright owners, this has not always been possible. The QAS would welcome notification from any copyright holder who has been omitted or incorrectly acknowledged.

All feedback and suggestions are welcome. Please forward to: Clinical.Guidelines@ambulance.qld.gov.au

Disclaimer

The Digital Clinical Practice Manual is expressly intended for use by QAS paramedics when performing duties and delivering ambulance services for, and on behalf of, the QAS.

The QAS disclaims, to the maximum extent permitted by law, all responsibility and all liability (including without limitation, liability in negligence) for all expenses, losses, damages and costs incurred for any reason associated with the use of this manual, including the materials within or referred to throughout this document being in any way inaccurate, out of context, incomplete or unavailable.

© State of Queensland (Queensland Ambulance Service) 2020.

Policy code CPG_TO_CCB_0120

Date January, 2020

Purpose To ensure a consistent approach to the management of calcium channel blocker poisoning.

Scope Applies to Queensland Ambulance Service (QAS) clinical staff.

Health care setting Pre-hospital assessment and treatment.

Population Applies to all ages unless stated otherwise.

Source of funding Internal – 100%

Author Clinical Quality & Patient Safety Unit, QAS

Review date January, 2023

Information security UNCLASSIFIED – Queensland Government Information Security Classification Framework.

URL https://ambulance.qld.gov.au/clinical.html

Clinical Practice Guidelines: Toxicology and toxinology/Calcium channel blocker

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives V4.0 International License

You are free to copy and communicate the work in its current form for non-commercial purposes, as long as you attribute the State of Queensland, Queensland Ambulance Service and comply with the licence terms. If you alter the work, you may not share or distribute the modified work. To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-nd/4.0/deed.en

For copyright permissions beyond the scope of this license please contact: Clinical.Guidelines@ambulance.qld.gov.au

247QUEENSLAND AMBULANCE SERVICE

Calcium channel blocker

Clinical features

Cardiovascular effects

• Bradycardia

• Heart block

• Hypotension

• Cardiogenic shock

Systemic effects

• Seizures

• Coma

• Hyperglycaemia

• Metabolic acidosis

Risk assessment

• CCB toxicity is potentially life-threatening, particularly if verapamil or diltiazem is takenwhich are more cardio selective.

• Older persons and those with underlying

cardiovascular disease are more at risk of severe toxicity.

• Co-ingestion of other cardiac medication such as ACE inhibitors, beta blockers or digoxin can cause severe toxicity.

January, 2020

Figure 2.72

Calcium channel blockers (CCBs) are commonly prescribed

medications used in the treatment of hypertension, angina pectoris

and cardiac arrhythmia.[1] In overdose they can cause severe

cardiovascular toxicity.

Examples:

• Verapamil

• Diltiazem

• Amlodipine

• Nifedipine

• Felodipine

• Lercanidipine

Most CCBs in therapeutic doses act to decrease blood pressure

through vasodilation. In overdose this can lead to hypotension and

vasodilatory shock.

Verapamil and diltiazem are particularly toxic as they also act on

calcium channels in the heart to slow the heart rate and decrease

myocardial contractility. In overdose they can cause bradycardia and cardiogenic shock.

Many CCBs are available as slow release preparations. Therefore, there can be a delay of many hours from time of ingestion before the onset of toxicity.

Calcium can ameliorate toxicity and is part of the treatment approach to severe poisoning. [2]

UNCONTROLLED WHEN PRINTED UNCONTROLLED WHEN PRINTED UNCONTROLLED WHEN PRINTED UNCONTROLLED WHEN PRINTED

248QUEENSLAND AMBULANCE SERVICE

CPG: Clinician safetyCPG: Standard cares

Ongoing imminentrisk of harm?

Transport to hospitalPre-notify as appropriate

Note: Clinicians are only to performprocedures for which they have received specific training and authorisation by the QAS.

Y

N

Manage as per:

CPG: Sedation − Acute behavioural disturbance

Consider:

• Verbal de-escalation

• QPS assistance

• Physical restraint

• EEA

Consider:

• Oxygen

• IV Access

Perform:

• 12-Lead ECG

• BGL

Bradycardia or hypotension?

N

Consider:

• IV fluid

• Calcium gluconate

• Atropine

• Adrenaline

• Transcutaneous pacingY

UNCONTROLLED WHEN PRINTED UNCONTROLLED WHEN PRINTED UNCONTROLLED WHEN PRINTED UNCONTROLLED WHEN PRINTED